New Tricks

SLCOM 1

It’s fair to suggest that recent developments in resin-based 3D printing had some industry experts at least contemplate, EnvisionTEC’s standing in the upper echelons of 3D printing manufacturer royalty. Many wondered what kind of effect Carbon’s promised speed, Formlabs’ consistent development or the heft Autodesk were putting behind Ember would have on one of the industry’s traditional big players.

When whispers began to circulate that EnvisionTEC was to launch something significant at RAPID, it was safe to assume that it would be an upgrade to its existing technology. That like 3D Systems with the SLA-bot1 it would launch its answer to the glut of systems using “Continuous” resin printing. However, As EnvisionTEC CEO, Al Siblani prepared to launch the company's brand new machine to the waiting RAPID crowd, it was evident from the gargantuan device too big to hide behind curtains that this would be a totally different beast.

“In keeping with EnvisionTEC's traditions of being first to market we're very excited to launch the brand new technology of SLCOM, which stands for Selective Lamination of Composite Object Manufacturing,” Siblani told TCT at the time. “It's a new technology that allows you to build thermoplastic reinforced composites with different types of fibres and different types of thermoplastics to create materials and parts that have never been done before in the Additive Manufacturing (AM) space.”

The SLCOM 1 is quite the departure for the company known for its high-resolution smaller machinery suitable for precision projects like jewellery and dentistry. This machine EnvisionTEC say is the first and only thermoplastic reinforced woven composite 3D printer, capable of manufacturing parts in materials like PEEK, Polycarbonate, fiberglass and carbon fibre.

Composing Composites

Traditional processes of manufacturing composite parts involve intensive manual labour and that’s after sheets have been cut using a CNC. Laying up sheets of differing composites over epoxy moulds cutting to exact size, vacuum sealing, baking and post processing is all done by hand. The advancements in materials available over the past decade have meant, despite the labour intensive process, it has been worthwhile to countless sectors from aerospace to sporting goods. Any ability to shorten the process would be thoroughly welcomed.

There are only a few other companies offering a composite 3D printing solution on the market at the minute; Markforged whose Mark One and Two series of printers are desktop machines that embed strands of composites into matrix thermoplastic materials; and Impossible Objects, whose beta machine takes sheets of composite material prints a thermoplastic onto each layer and is then baked in the oven in order to fuse the layers together.

EnvisionTEC’s SLCOM1 is a step towards a more industrial offering from a company with almost two decades of building machinery. With an impressive build envelope of 24 inches in Y, 30 inches in X, and 24 inches in Z Al Siblani said the machine’s sizeable build volume was “significant enough to appeal to many industries.”

Using rolls of pre-impregnated thermoplastic composites, there are three main obvious innovations in the mechanics of the SLCOM 1; the use of an ultrasonic cutter to eliminate fraying

on the cut of the thermoplastic sheets; a rotating platform that allows for multi-directional layering of the composite sheets, which can be turned clockwise and counter clockwise in 15 degree increments thus significantly increasing strength; and the use of an inkjet-like head to spray an anti-adhesive around the outside of the plotted layer inhibiting the next sheet from sticking to that area, meaning removal of the excess material (AKA decubing) is exponentially easier.

Those are significant advancements in the hardware but perhaps, as all good magicians they’re acting as a distraction to another very revolutionary and hugely important part to SLCOM technology, the ability to deliver bespoke materials to the customer. Because of EnvisionTEC’s unique laminated roll system a customer can demand any combination of prepreged thermoplastic including PEEK, Nylon, polycarbonate mixed with the desired fibre making the SLCOM 1 a hugely versatile machine for the customer.

Runway to success

The manufacture of composite parts is a massive departure for EnvisonTEC this much is clear, but it is one that has been carefully deliberated and seemingly impeccably executed. Al Siblani told TCT more at RAPID:

“When you look at the 3D Printing and AM space in general we found that there's a huge attraction in metal AM especially coming from the aerospace sector,” said Siblani. “But there are too many players in that space. We thought about an area where we could go and develop a technology in an uncrowded space and when we looked at the composite market, specifically carbon fibre and fibreglass we found out that there's no actual player in the space for AM and given that aerospace companies spend 50% or more of their budget on composites we thought that would be the right place for us to invest in.”

Siblani, like all CEOs, has always talked a good game so perhaps we should take that 50% as ambitious but if the Boeing 787 is anything to go by then that stat is dead on the money. The “Dreamliner” – Boeing’s largest passenger jet is made up of exactly 50% composite parts, the previous model, the 777, was made up of just 12% composite material. Boeing’s main rival, Airbus, are currently flight testing the A350 XWB that comprises of 53% composite material, not only that but the XWB is the same plane that we were told has over 1,000 3D printed parts on board from the Concept Laser’s LASERcusing bracket to the Stratasys’ multiple FDM internal parts.

In her 2013 report into “The use of composites in aerospace: Past, present and future challenges”, Dr Faye Smith of Avalon Consultancy Services Ltd concluded that: “Environmental regulations have meant that the cost of introduction of lightweight composite structures is now often offset by the gains and has significant increase in the use of aerospace composite structures.” But that a current challenge was the “development of rapid rate manufacturing process.”

Plenty are trying to create a solution for this challenge, Hexcel – one of the largest suppliers of carbon fibre in the US – have announced, a strategic investment in Oxford Performance Materials to advance composite 3D printing in aerospace with Hexcel’s CEO commenting; “Aerospace adoption of reinforced manufactured parts using Hexcel carbon fibre is becoming a viable and meaningful design solution due to its performance and processing advantages. With the adoption of these lightweight, high-performing materials expected to accelerate, this is an ideal opportunity for our two companies to work together enabling faster product development and adoption for our customers.”

It comes as no surprise then that Al Siblani told TCT at RAPID, “There's a lot of people in many industries that have expressed excitement in SLCOM technology already. We've had some great and amazing reaction from the aerospace industry.”

By not joining the metal 3D printing game, circling, the airport, waiting to land that major aerospace client, the SLCOM technology has EnvisionTEC signalling them in to their own private airfield. Of course, there’s room for both technologies on the factory floors of conglomerates like Airbus and Boeing each offering their own unique features. SLCOM, for instance, is unlikely to be able to create the complex internal structures that generative design creates.

The SLCOM 1 project has been in the making for a number of years and goes someway to explaining why EnvisionTEC staff seemed to exude a confidence in their company like no other, they knew they had a trick up their sleeve that they’d shock the industry with.

There are several reasons why EnvisionTEC were able to keep SLCOM under their hats for so long, firstly Al Siblani likes to demonstrate running technology rather than concepts at trade shows and it is likely that the SLCOM 1 was only finished shortly before being displayed at RAPID. Plus, unlike many of the other industry big boys, EnvisionTEC is a private company, in an interview with the BBC recently the top British fashion designer, Paul Smith, said that a big advantage of still being a private firm is that you don't have "shareholders breathing down your neck the whole time", the same may well apply to Al Siblani and company, they don’t have to placate anyone every single time a new piece of technology comes to market, they can go about their business quietly and efficiently.

And for their next trick, less than a month after RAPID, EnvisionTEC announced that Continuous DLP method we were all expecting them to.